Overview
Hi, I'm having a pretty annoying problem with my setup where I can't get anything from my RSE/VES system to play up into the headunit (and therefore can't get it to play through the vehicle speakers when my kids are watching movies in the back).

Details
I had the Maestro RR set up professionally with the CH1 and AV-CH1 adapters to connect a new Pioneer AVIC-8200NEV to my 2015 Town and Country with VES system (which has a factory Blu-ray drive). Everything about the RR and CH1 are working fine including steering wheel controls, but I'm having issues with the AV side. Specifically, I am not able to get any thing from the VES/RSE system to show up on the head unit. This is a major problem for me, as having the VES system to play Blu-raysfor my kids is actually the main deciding factor for why we bought the car in the first place.

Anyway, here are the symptoms and what I have tried to eliminate as causes:

The Blu-Ray player in the VES system itself is working -- I can still watch movies on the rear screens using the factory BD player with no issue (while listening to them with the car's wireless headphones)

The other inputs (HDMI, component) in the rear of the vehicle also work -- I tested this by attaching my old PS2 and new Chromecast to them and viewing them on the rear screens

The AV input on the head unit also works fine -- I tested it by pulling out the head unit to expose the back (while leaving it plugged in) and attaching my old PS2 to the input plugs directly on the back of the unit

The car's VES harness cable is also working -- I tested this by disconnecting the Maestro and Pioneer and temporarily re-connecting the factory head unit to all the harnesses and verifying that I could watch the rear VES system on that head unit (with its sound coming out the car's main speakers, as expected).

The AV-CH1 cable itself seems to be at least partially working -- I tested the AV OUT part of the cable by playing a DVD in the Pioneer head unit, setting the Rear source on the head unit to DVD and setting the inputs on the rear screens to be "DISC" (Not "VES DISC" which refers to the factory Blu-ray player) and this works (for video and audio);

The backup camera is also working fine

The AV Input in the Pioneer settings menu is set to "Source" (not "Camera" or "Off"), which should be the correct setting

The OEM Settings menu does work in controlling each screen the VES system -- I have verified being able to change the inputs for both 2nd and 3rd row screens as well turning the VES system on and off from the menu. Since I haven't been able to see anything on the head unit, I haven't been able to verify that the "Radio Screen" menu control is working, but the status of which inputs are occupied is correct when items are plugged into the rear inputs, so some information is travelling.

Literally the only thing not working is the AV signal not getting from the VES to the head unit -- neither the VES Blu-Ray player or the rear inputs show up; Every other piece of functionality appears to be working correctly.

Also, I'm pretty sure that it is not my particular AV-CH1 cable. I bought a second one just to make sure and I'm getting the exact same symptoms with that one swapped in.

Is there something I'm missing in the settings or when configuring the system that could be causing this? It seems impossible that I'm the only one having this problem, but I can't find any mention of it in other forums or threads.

Sorry for the long post, but I just wanted to be thorough and clear. Please help!

are you using the AV input of the radio (has the 3 rca's coming off the back) or the Aux In (the 3.5mm opening, requires a 3.5mm to a/v rca adapter that isn't included with the radio)?

Is the backup camera being displayed on the radio when you go into reverse? If so, I would put the van in reverse (so it shows the backup camera view), disconnect the camera and put the video output of the VES into the camera input and see if you get video from the screen.

You've done a good bit of troubleshooting which is refreshing to see, it seems like it could be a setting based on what you have done so far.

To your first question, I'm using the AV input (the 3 RCA's). Actually, I had a backup plan of switching it over to the AUX in because I thought that the problem may have been the AV input itself (and I bought the 3.5-AV adapter to do that). However, I have since directly confirmed that the AV input RCA jacks are working (with the PS2 test I mentioned in my original post), so now I'm just keeping the adapter to use in a "just in case" situation. I guess I could still do that test and see what comes up.

That's a good idea to check with the backup camera (which, yes, it is showing up on the radio when I go into reverse, btw). I will try that test once I get home tonight to see what happens there.

The crazy thing is that after going through all the troubleshooting, no one single part of the setup seems like it's incorrect or broken -- just when I put them together, no dice. I guess the next step for me from here depending on these tests is to re-flash the Maestro, dig through the head unit settings again and cross my fingers? I'm at a loss!

Thanks for the suggestions, all, but I'm not sure that this is the case. I think this based on a few reasons:

I have been running these tests in my garage with the parking brake engaged the whole time (though now that I think about it, I might have seen a "Parking Brake" connection wire from the HU that wasn't connected to anything, hmmm, maybe worth investigating).

I have already tested the AV connection itself by hooking up a PS2 directly to that connection (if you look at my first post, I mention this). I was able to confirm in that situation that the AV in connections do in fact work. (I was able to see and hear the PS2 on the AV selection on the HU and out of the car's speakers)

I am unable to see OR hear anything on the AV connection when the AV-CH1 is connected to it. I can understand the video being turned off based on the parking brake, but it wouldn't make sense for the sound to not be coming out either, right?

Anyway, it is worth investigating and I found out a way to bypass the parking brake lock, so I will try that out soon.

And btw, just to add to the mystery, this weekend I was able to finally getting around to hooking up the AV-CH1 to the AUX input (via an RCA-to-3.5mm adapter I purchased via Amazon) rather than the AV inputs in order to see if that would be a workaround. And lo and behold, the audio from the AV-CH1 works via the AUX input! The video doesn't work, but I think that might be because the video and ground connectors are swapped on the adapter from what the HU expects (when I plug in the yellow video cable, I hear rhythmic static, which indicates to me that something is going to ground that shouldn't be). This works for now as a stop-gap, but I would really like to get to the bottom of this.

The plot thickens! Next test is the parking brake bypass, but after that I might have to take it back in to get the guys to check their wiring and the unit or complain to Pioneer and maybe get a new HU?

Sorry, I forgot to state that explicitly, but yes, I'm pretty sure that I had it set to VES DISC. When I'm trying this out, it's the only active selection, since I usually don't have anything attached to the other inputs in the back of the car (HDMI and RCA).

okay so i just want to make sure that i am understanding this. You can feed audio and video signal from the aftermarket radio into the VES system and all works good. However, when using the factory BluRay player we can not get it to play on the radio screen and through the audio system?

It sounds like we just an issue with the VES configurations. When we are playing the DVD from the BluRay go into the VES Settings found in the Vehicle Feature Menu and see if we can mess around and change the settings there until we get it. Cycle between Aux inputs and VES DISC and make sure it holds after you make the setting.

I am fairly certain to have already eliminated that as a possible cause. I have fidgeted with the VES settings repeatedly in order to test this. Additionally, as mentioned, I am getting the sound (at least) to play through the headunit when I connect it to the AUX input (not AV input), so the VES setting is correctly set, I believe. I can try out your specific suggestion when I get home, though.

So I went and tried your suggestion and I am unable to select any of the other VES display options in the OEM Settings menu because, as I have mentioned before, I don't have anything else plugged in to the ports in the back of the car. Therefore I am still at square 1.